<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        // let set = new Set('a', 'b');
        // console.log(set);//a

        let set = new Set(['a', 'b']);
        console.log(set);//a,b

        set.add('wang');
        // set.delete('a');
        // set.clear();
        // console.log(set[0]);
        console.log(set.keys());
        
        let keys = set.keys();
        // for (let key of keys) {
        //     console.log(key);
        // }
        console.log([...keys]);
        let rset =[...keys];
        
        console.log(set);
        console.log(set.has('aaa'));
    </script>
</body>
</html>